In the world's breadbasket, climate change feeds some worry

Sep 5, 2011, 12:21 p.m.

A field of corn is shown from the motorcade carrying U.S. President Barack Obama in between stops near Monona, Iowa, August 16, 2011. REUTERS/Jason Reed

Takle said Midwest farmers are already adapting.

"Farmers say they don't believe in climate change, but you look at how they spend money and are adapting," he said.

Takle pointed to bigger machinery to allow faster and denser seeding amid rainier springs in the Midwest. Frosts are trending later so crops are kept in fields longer to dry.

But many of the changes are more subtle and hidden than the weather events that grab the headlines, like the massive wildfires, flooding and tornadoes that have hit agricultural areas of the Midwest, Plains and Southwest this year.

Takle said measurable trends of more humidity, for example, has led to higher night-time summer temperatures in the Corn Belt and likely trimmed corn yields in recent years. Corn likes hot days but cool nights.

In Iowa, dew point temperatures have risen 3-1/2 degrees Fahrenheit in the last 35-40 years, equating to 13 percent more moisture in the air during the summertime, he said.

"It's very important that we recognize the vulnerability," Takle said. "We have situations like in Texas. Huge reservoirs have just vanished. You can't do a work around."

The U.S. Agriculture Department this year issued its first grants to study crops and climate change.

"If you're interested in adapting to changes in climatic norms you need to have access to diversity," said Randy Wisser of the University of Delaware, who will study the genetics in exotic tropical maize to see how this might help farmers.

Other grants will address greenhouse gas emissions that affect climate, notably methane from livestock and carbon dioxide from growing crops.

"We are just trying to find a suitable way to keep these farmers in business. It took generations to create the problem it will take generations to fix the problem," said William Horwath of the University in California, who will develop strategy for rice growing in the Sacramento-San Joaquin Delta.

"It's a pretty darn complex problem," Hatfield said. "We poke at it, but we need to get very serious about how do we think about adapting our crop production goals to the concepts of variability."